1. Field
An aspect of the present disclosure relates to a secondary battery.
2. Description of the Related Art
As the miniaturization of portable electronic devices has progressed, much research has been conducted to develop secondary batteries for such portable electronic devices.
Unlike batteries that are not rechargeable, secondary batteries are rechargeable and are widely used in portable electronic devices, such as cellular phones, notebook computers and camcorders. Particularly, lithium secondary batteries have an operating voltage of 3.6 V, which is three times higher than that of nickel-cadmium batteries or nickel-hydride batteries. Lithium secondary batteries have an excellent energy density per unit weight, and therefore, the use of the lithium secondary batteries has rapidly increased.
In such lithium secondary batteries, a lithium-based oxide is used as a positive electrode active material, and a carbon material is used as a negative electrode active material. Lithium secondary batteries are manufactured in various types, such as a cylindrical, prismatic, and pouch-type.
A cylindrical type secondary battery includes an electrode assembly, a cylindrical type can, a cap assembly, a gasket, and the like. As disclosed in Korean Patent Laid-Open Publication No. 10-2007-0071235, and the like, a general cap assembly includes many components, such as a safety vent, a current blocking unit, a secondary protection device, and a cap-up. Therefore, manufacturing costs are increased and manufacturing efficiency is reduced.